SBOU281 May   2022

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Features
    2. 1.2 EVM Specifications
  3. 2Power Connections
    1. 2.1 Split-Supply Operation
    2. 2.2 Single-Supply Operation
  4. 3Input and Output Connections
    1. 3.1 Bias Mode Control Pins
    2. 3.2 Optional VCM Connection
  5. 4Schematic and Layout
    1. 4.1 Schematic
    2. 4.2 Layout

3 Input and Output Connections

The DEM-OPA-RGV-EVM is equipped with footprints for SMA input and output connectors for simple interface to signal generators and analysis equipment. Typically test equipment has 50-Ω termination, so footprints for matching resistors R1 and R2 at the input as well as R15 and R16 or R41 at the output are provided to created matched impedances in any configuration. For best results, signals must be routed to and from the EVM with cables with a characteristic impedance of the same value as the test equipment and board.

The board has two input SMA footprints for a dual channel amplifier. To set the amplifier in a non-inverting configuration, populate R4 and keep R3 and R20 unpopulated for channel A. For channel B, populate R9 and keep R10 and R36 unpopulated. The opposite can be modified to set the amplifier in a inverting configuration for both channels.

Both channels can be configured for either a differential input connection or as single-ended input individual channels. To use the device with a single-ended input, populate either R20 or R4 for Channel A and R36 or R9 for Channel B depending on amplifier configuration (inverting or non-inverting). If interfacing with a differential input, populate resistors R5 and R8 and apply a common-mode voltage, VCM, by following the steps detailed in Section 2. Differential input components R7 and C14 will also need to be populated in this configuration.

The board can also be configured for either a differential output connection or as single-ended output individual channels. To use the device with a single-ended output, populate the transformer, T1, and keep C15 and C18 unpopulated. OUT_A (J6) can be the connector to the equipment with R38 populated. If interfacing with a differential output, populate C15 and C18 with shorting resistors or DC-blocking capacitors. Both output SMAs should be populated and keep R35 and R38 unpopulated.